'Green Zone'

BACK STORY: Greengrass has taken the seemingly unfilmable -- the Sept. 11 attacks, in particular, with his "United 93" -- and made movies that are critical and commercial successes. He faces one of his toughest challenges yet with "Green Zone," a big-budget drama set in post-invasion Iraq.

You need only a passing familiarity with Hollywood economics to know movies about Middle East conflict have not fared well at the box office. But Greengrass doesn't see this very, very loose adaptation of "Imperial Life in the Emerald City" as a war movie. Instead, the British filmmaker says, it's a thriller that happens to involve a search for weapons of mass destruction: Jason Bourne in Baghdad, in other words.

"The purpose of this film is not to have a view of the Iraq war," says Greengrass, who recently bowed out of a fourth "Bourne" movie, having directed "The Bourne Supremacy" and "The Bourne Ultimatum," both of which starred Damon. "It's to take this world and explore a story inside it."

Damon is a U.S. Army officer whose team of inspectors aren't simply looking for a needle in a haystack: They also navigate through subterfuge, politics and coverups.

"The hope is to make a strong, contemporary thriller that is set in Iraq, because thrillers thrive on extremes, and there is no more extreme environment than immediate postwar Baghdad," Greengrass says. "To me, the most interesting thing about the film is to marry the demands of powerful thriller storytelling with the demands of setting a story in the real world. But this is not a movie about Iraq."

FILM CLIP: As is his custom, Greengrass shot miles of footage and the "Green Zone" editing process took so long, the film's release was delayed from last year.